A gas turbine engine such as that used for powering an aircraft in flight, for example, includes numerous tubes for channeling various fluids through the engine during operation. Conventional clamps are used for mounting the tubes to the engine casing, at standoff brackets for example, to accurately position the tubes and prevent their movement during operation of the engine.
Since the gas turbine engine includes various rotating components, the tubes are subject to vibratory excitation which must be controlled for preventing vibratory fatigue damage thereto. One exemplary conventional tube clamp used in an aircraft gas turbine engine has two clamp halves pivoted together at respective first ends thereof so that the clamp halves may be opened for inserting one or more tubes therebetween, and then pivoted together to capture the tubes. Each clamp halve typically includes a generally semicircular recess which collectively surround a respective tube, and a fastener hole extends through the tube clamp halves so that a suitable fastener, such as a bolt, may be inserted through the holes, with a complementary nut joined to the bolt for clamping together the two clamp halves around the one or more tubes therein. The fastener typically also extends through an engine mounted bracket for joining the tube clamp and the tubes therein to the engine casing.
Conventional tube clamps are typically made of suitable metals such as aluminum, stainless steel, or Inconel which are selected for use in the engine depending upon the temperature of the individual location from relatively cool near the fan of the engine to relatively hot near the combustor and turbines thereof. Since metal tube clamps are known to abrade or chafe the tubes contained therein due to vibratory excitation of the tubes during engine operation, a conventional wear sleeve, made of epoxy for example, is positioned between the tube and the tube clamp to prevent undesirable wear of the tube during operation.
These conventional tube clamps including wear sleeves are relatively complex in structure, manufacture, and assembly thereof, and collectively add substantially to the weight of the engine. The wear sleeve is an additional part and must be suitably secured to the tube to prevent its liberation therefrom during operation of the engine which is undesirable. Furthermore, metal is known to be a poor vibration damper, and therefore the metal tube clamps provide little vibratory damping of the tubes contained therein being subject to vibratory excitation during operation of the engine.